# What size feeder do you use for a 200 amp panel box?

A three ought (000) copper wire with an insulation factor of 90 degrees C has an amp rating of 210 amps.

### Can you tap off of a 200 amp service for 2 100 amp panels?

Yes, but at every reduction in wire size there has to be a breaker sized to the smaller wire size. The wire size for 100 amp panels is recommended at #3 copper conductor. From the 200 amp feeder panel you will require a 100 amp two pole breaker for each of the two 100 amp services. Keep in mind that if you run the 100 amp services close to maximum this will take away the…

### Do you need to change the wire size going from 100 amp service to 150 amp service?

Yes, the wire size has to be increased. The existing 100 amp service will now probably have a #3 conductor with an insulation factor of 75 or 90 degrees C which is rated for 100 and 105 amps respectively. Increasing to a 150 amp service will use a #1/0 wire size. If you are thinking of an upgrade, skip the 150 amp service and go to a 200 amp panel. New homes are installing 200…

### What would happen if a 200 amp breaker is used in a 100 amp sub panel?

There are two things to think about here. First of all a 200 amp breaker will not physically fit into a 100 amp panel. This is so designed because the panel buss is not designed to conduct 200 amps before the current is cut off. A 100 amp rating on the panel is the maximum amount of current that the manufacturer states, that can be handled safely. Second if the 200 amp breaker is in…

### How do you determine if you have 100 or 200 amp service?

Look at the value of the breaker or fuses that control your main electric panel. look at the wire size coming in to the main lugs on service panel, I am assuming you don't have a main breaker or you would look at the breaker rating to determine service size. 2/0 copper or 4/0 aluminum service size 200 amps, #4 copper or # 2 aluminum 100 amp.